GB638081A - Improvements in or relating to glassware lehr - Google Patents

Abstract

638,081. Glass-annealing leers. HARTFORDEMPIRE CO: July 14, 1947, No. 18733. Convention date, July 8, 1939. [Class 51 (ii)] A glass-annealing leer, in which heating and cooling gases are circulated, comprises means associated with the entrance end of the tunnel for supplying heated gases and circulating them about the ware on the conveyer, a series of independent muffles completely surrounding a subsequent section of the tunnel and means for passing cooling gases in the muffles entirely around the tunnel. The leer shown comprises a tunnel 11 divided into a conditioning zone heated by three sets of transversely-spaced, rearwardlydirected burners 18, a slow cooling or annealing zone, a muffled cooling zone and a rapid cooling zone, the ware being transported on an openwork conveyer 15. The slow cooling zone is heated by burners 20 in passages formed by cover blocks 21, these burners being arranged to produce a transverse circulation of the tunnel atmosphere which may be assisted by jets of compressed air supplied by a fan 22. The means for the supply and discharge of air in the rapid cooling zone are as described in Specification 491,954, and comprise longitudinally-extending pipes 27, 28 fitted with nozzles 29 through which air jets are directed against central baffles 30. The muffled cooling zone comprises a series of transverse muffles, Figs. 4 and 5, having bottom passages 34 provided with damper-controlled openings 37; side passages 35 and top passages 36 each communicating with an exhaust stack 39 controlled by a damper 40. Compressed air supplied from the fan 22 may be admitted through jet nozzles 41 to accelerate the flow through the muffles. The bottom wall 32 of the tunnel may be of metal and the side and/or top walls of heatinsulating material so that the ware is subjected to a greater cooling effect at the bottom than at the sides. Alternatively the walls may be of unequal thickness. The pipes 27, 28 and baffle 30 may extend into the muffled cooling zone.